An Analytical Framework for Assessing Biogas Potential from Consumer Food Waste in US Cities

Consumer-side food waste—cited anywhere from 20% to 40% of all food production—is a potential renewable fuel source that could offset significant energy needs in urban areas. Anaerobic digestion is a proven method by which biogas can be produced from food scraps. Currently, logistical challenges and costs make implementing city-wide consumer food waste collection and use limited.

However, many US cities already have composting programs which collect food waste and compost it to make fertilizer and high quality soil. In addition, many cities have ambitious goals and initiatives to significantly reduce their waste and greenhouse gas emissions in the upcoming decades. The use of food waste to produce biogas would help cities to simultaneously meet both of these objectives. In this study we establish an analytical framework for assessing the energy availability from consumer food waste in US cities and examine the potential for displacing existing natural gas usage with biogas derived from consumer food waste through anaerobic digestion. Results will include an estimation of available consumer food waste, potential to meet demand using produced biogas via a comparison with existing natural gas usage, and potential emission reductions from both reducing food waste in landfills and displacing consumer natural gas usage. Results will help inform city policies for establishing various food waste collection and use programs.